Pneumatic tool.



PATENTED JULY 10, 1906.

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UNITED sTArns PATENT OFFICE.

HERMAN LEINEWEBER, OF SOUTH CHICAGO, ILLINOIS,. ASSIGNOR TO INTERNATIONAL TOOL COMPANY OF CHICAGO, A CORPORATION OF ILLINOIS.

PNEUNIATIC TOOL.

Specification of Letters Patent.

ratenteu July 10, 1906.

Application filed March 20, 1905. Serial No. 251.048-

To a/ZZ whom it may con/cern:

Be it known that I, HERMAN LEINEWEBER,

a citizen of the United States, residing at South Chicago, in the county of Cook and State of Illinois, have invented a new and useful Improvement 1n Pneumatic Tools, oi

which the following is a specification.

My invention relates to an improvement in i the class of pneumatic hammers in which a 5 piston confined in a easing is actuated by airpressure to reciprocate against a tool te drive E it, such as a riveting-tool, a chisel, or the like, in the end of the casing.

I have devised my improvements with reference to the pneumatic tool forming the subject of Letters Patent No. 778,319, granted to me on the 27th day of December,.1904, though they are not limited to use with that particular construction of the tool.

My object is to improve a pneumatic tool of the gentral construction of that set forth in the aforesaid Letters Patent in matters of detail.

Referring to the accompanying drawings, Figure l is a top plan view of a pneumatic tool containing my improvements. Fig. 2 is a section taken at the line 2 on Fig. I and viewed in the direction of the arrow. Fig. 3 is a view like that in Fig. I, but presenting the opposite side of the implement. Figs. 4, 5, 6, 7, and 8 are sections taken, respectively, on the lines 4, 5, 6, 7, and 8 in Fig. 2 and viewed in the direction of the arrows. Fig.

9 is a section taken at the line 9 on Fig. 2 and viewed in the direction of the arrow, and Fig. 10 a broken section taken at the line 10 10 on Fig. 4 and Fig. 5.

A is the casing, having a desired tool B, shown broken, and which may be a rivetingtool, a chisel, or the like, seated in its distal end in a bushing o. therein provided with a shoulder a and through which the stem b of the tool passes into an enlargement forming an air-chamber c in the casing. The bushing a abuts against an annular shoulder d, forming the forward end of the chamber c and through which the tool-stein passes, the shoulder serving a purpose hereinafter explained. The junction of the tool with its stem forms a shoulder a2, from which a longitudinal groove e, formed in the tool-stem, extends short of its inner end, the groove being inclined-at its ends, and into this groove projects a spring-pressed studf, COniined in a tubular nut g, screwed through the casing and the bushing a.

By the construction thus described the tool is held against dropping out of the casing when the implement is out of operation and carried with the tool end downward, and the stem I), being beveled on its end at may be readily inserted in place through the bushing, since the act of inserting it raises the studf out of its path andthe spring about the stud snaps the latter into engagement with the groove d when it -comes into registration therewith. Moreover, when the implement is out of use and the tool is in its position of extreme protrusion the inner end of the stem is within the area of the annular shoulder d, so that in the event of accidental forward 'shooting of the piston C, hereinafter described, its end will encounter the shoulder instead of the tool-stein, whereas if it should then encounter the stem the force would tend to drive the tool out of the casing with possibly resultant damage to the implement and injury to any object the tool might strike besides inconvenience owing to the loss of the tool, even though only temporary, particularly if the operator is using the implement on elevated work, whence it drops.

The reciprocating piston C, which closely fits inside the casing, contains a plurality of longitudinal air-ducts h, each terminating at its ends, respectively, in elongated lateral openings 7L h2, through which the driving airpressure passes alternately in contrary d1- rections, exhausting when. the openings h register in the movements of the piston with an annular groove t', formed in the inner wall of the casing near the chamber c therein, the exhaust-air passing through ducts i', of which three are shown, formed longitudinally in the wall of the under side of thecasing and lead ing to a plurality of small discharge-ports It in the casing-wall, the exhaust taking place from the openings h2 when they register With an annular groove l, formed in the inner casing-walland with Which the three exhaustducts i communicate, as also two additional ducts l which lead to discharge-ports 7c.

D is the handle on the end of a hollow head A in the form of a sleeve fitting about the re ar end of thec'asing and reaching nearly to a shoulder m, adjacent to which the head is screw- IOO threaded, as shown at y. The head contains l in its outer end portion an air-chainber n, larger than the chamber c, and intoit projects lcentrall y from the handle-equipped end ol the head a thiinble 0, the bore of which is of a diameter adapting it to receive the adjacent end of the piston for cushioning the back stroke of the latter. ()n the under side ol'- the handle near its base is provided a nipple y), with which to connect the hose, (not showin) through which air-pressure is supplied from a suitable source to the implement, and from this nipple therev extend across the base ol" the handle air-ducts i] q, terminating in an enlargement q on the opposite side of the handle-base, containing a bushing q2, which forms a seat for a spring-pressed valve r, the stem 1" of which protrudes beyond the top of' the head A, underneath the valve-operating lever E, fulcrumed at and housed iii a recess s, formed in the. top of the hande l) and beyond which' only the thumb-bearing s on the free end projects to be accessible to the thumb of the oilierator. The recess s termi.- nates in an enlarged cavity s2, formed in the top of the handle, in which the thumb-piece fits and which affords a guide for the thumbpiece in depressing it to direct it regularly and prevent the thumb from exerting torsional pressure against it, which. Would tend to disorganize the lever. ly thus shielding' the lever E between the sides ol' the. recess s it is not lia-ble to injury by bending or breaking in the event of dropping the implement.

An air-diict t is provided in the bushing q2, and from it lead branch ducts t t, longitudinally in the wall of the head A to branches t2, extending at right angles to the branches t and registering with a'pocket t, formed in the outer wall of the casing, fromwhich pocket extend longitudinally in the casingwall continuations t4 t4 of the ducts t to an annular air-feed chamber F,\formed in the inner Wall of the casing between the exhaustgrooves Z and fi.

With each row of small exhaust-ports c, provided in the casing 'at an end of each of the five exhaust-passages i and l', there registers a similar row of ports k', formed through the wall of the head A. It is advantageous to provide these exhaust-ports on the under part of the implement instead of on a `/lateral side thereof, since thereby the' air which exhausts through them with considerable force does not blow against the body of the operator and saves h iin from consequent discomfort, and the provision of these ports in large number of small size tends to protect the internal working parts of the implement against dust, 'chippings, and other foreign matter, which 'is inore liable to enter the casing through larger eXhaustports, particularly when provided in a side of a casing, since then when the implement is out of use and laid on the opposite side, leaving the eX- haust-ports uppermost, foreign matter is more liable lto enter them by gravit-y than' when these ports are laterally disposed.

The handle-equipped tubular head A is fastened in place by a nut u, screwed upon its threaded end y against the shoulder m. For further holding the headv against turning a headed screw 'u is inserted through it at its under side, the head being angular, as shown at fe in Fig. 2, and entering a slot el, provided to receive itin the. outer wall of the casing A. The screw v affords a means for accurately registering the ports li" with the ports To secure the nut u against accidental turning with the result of loosening and disengaging the parts while the implement is in action, 1t is provided with a circuml'erential f series of notches u and with tl iesc notches engages a spring-pressed headed stuil w, having its bear-ing in a lip w', projecting over the nut from the forward end of the head A. 'lo rclease the nut from the stud w, the latter is raised against the resistance of its controlling-spring out of engagement with the notches u, and by turning it partially aroundv when thus raised two diainetrically opposite teats 102 on the under side of itshead which enter recesses in the lip in the normal position of the stub will bear against the top of the lip w to prevent the spring oll the stud from snapping it back into place until it is turned back. A s panner-recess 2 is shown to be provided in the nut to facilitate turning it through the medium of a spanner-wrench.

The exhaust-grooves afford a desirable feature of iin rovelnent, inasmuch as the piston C cannot )e so close-fitting as to prevent airpressure from a chamber e or n from leaking past it and getting ahead of it to obstruct its action, and these grooves intercept any such leakage air and immediately direct it through the exhaust-passages to the ports k r, there- `by constituting each groove a leakage-intercepting groove'.

The operation is as follows, with the parts in thel relative positions in which they arerepresented in the drawings y: On pressingthe lever E to open the valve 1? air-pressure llows through the assages q, g', t, t t2, t3, and t* into the fee ing-chamber F, whence it enters the piston-openings i2 and passes through t e piston ducts h, discharging therefrom at the openings h into the chainber c and Y Vlucing the back stroke of the piston, wnic.. zeible o, driving ahead of it into the latter suiV ient air from the chamber 'n to cushion the stroke and take' the im )act thereof off the hand of the opera tor. s the forward end of the piston clears the groove i, all air under pressure contained in the chamber c exhausts.. by Way of that oove and the passages 7153 connected therewith, through the ports" k 7c When the back strokeof the piston brings `its openings i into registration With the feeding-cham- IOO IIO

ber F, the pressure-supply therefrom passes at those openings through the piston-ducts and discharges at the openings h2 into the chamber n to drive the piston forward against the tool B, the air in the chamber n exhausting when the piston clears the groove l by way of the latter through the passages i and Z, communicating therewith, and the ports k 7c', to which those passages lead. The number of exhaust-passages leading from the chamber n is greater than the number thereof leading fromthe chamber c, because of the greater capacity of the rear chamber and the larger quantity of pressure requiring to be lexhausted therefrom in a iven time. i What I claim as new, and desire to secure by Letters Patent, is'- l. In a pneumatic tool, the combination with the casing containing a reciprocating piston and air-chambers at opposite ends thereof, to which the actuating air-pressure is fed through the piston, and from which Vsaid pressure is exhausted, of an impactshoulder in the forward chamber, a bushing seating against said shoulder, a tool inserted at its stem into the casing through said bushing and shoulder, said stem containing a longitudinal groove, a tubular nut screwed through the casing into said bushing, and a spring-pressed stud confined in said nut and working through the casing and bushing to engage said groove, for the purpose set forth.

2. In a pneumatic tool, the combination with a casing provided with air-chambers in its opposite ends, of a reciprocating piston within the casing, containing a longitudinal air-duct terminating at its ends in elongated lateral openings in the piston, an air-feeding chamber formed in the inner casing-wall between said end chambers and communicating with the air-pressure supply and from'which l the piston-actuating pressure alternately enters said air-chambers through the pistonduct, an annular leakage-intercepting groove formed in the inner casing-wall between said air-chambers, and an exhaust passage in said wall leading from said groove.

3. In a pneumatic tool, the combination with a casing provided with airechambers in its opposite ends, of a reciprocating piston.

within the casing, containing a longitudinal air-duct terminating at its ends in elongated lateral openings in the piston, an air-feeding chamber formed in the inner casing-wall between said end chambers and communicating with the air-pressure supply and from which the piston-actuating pressure alternately en-' ters said air-chambers through the pistonduct, forward and rear annular leakage-intercepting grooves formed in the inner casing-wall between said air-chambers, an exhaust-passage leading from said forwardl groove and an exhaust-passage leading from said rear groove. Y

4. In a pneumatic' tool, the combination with the casing containing a reciprocating piston with an air-chamber inthe forwar end of the implement and a relatively larger air-chamber in the rear end thereof, to which chambers tlie actuating air-pressure is fed through the piston, of exhaust-grooves in the inner casing-wall at opposite sides of its transverse center, exhaust-passages leading from the forward groove and a greater number of exhaustassages leading from the rear groove7 and a p urality of relatively small exhaust-ports formed in the Wall of the implement and at which said passages terminate, for the purpose set forth.

HERMAN LEINEWEBER. In presence of J. H. LANDES, J. W. DYsENroRTH. 

